Coin slide construction



March 25, 1969 M. A. HALL COIN SLIDE CONSTRUCTION Sheet Filed Deo.

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March 25, 1969 M. A. HALL 3,434,579

lCOIN SLIDE CONSTRUCTION Filed Dec. 4, 1967 sheet Z gf 2 FIG-Il @p2 '26 712 24 26 34 36 30' a 4 a4 324483 73 2f 3,4 36x 3Q 8 24 3;# 3;@ O sa 54 2f 3.4 31650 I23 kw x' K\ Y \g L l /04 n2 /0 /06 /08 ll/l/ 4l/6 /NvE/vof? /fa la "226 MITCHELL A. HALL U.S. Cl. 194-92 15 Claims ABSTRACT OF THE DISCLOSURE The coin slide mechanism is characterized by coincalipering arms of stiff spring wire which is resilient and flexible in all directons transverse to its length, said arms having free ends biased against a cam surface within limits imposed by a stationary restraining bar track. The resilient caliper arms at their free ends are movable toward and from one another while biased against the track, to actuate a pair of slide plate control latches which limit advancement of the slide plate whenever unacceptable coins or slugs are advanced for calipering, and when no coins are advanced by the slide plate. The latches, though normally movable by the resilient caliper arms to latch and unlatch the slide plate, are themselevs adapted to ex the caliper arms under certain conditions of slide plate abuse, to prevent damage to or permanent distortion of operating parts of the calipering and latching mechanism. The caliper` arms may be formed of resilient stainless steel wire, or equivalent.

The present invention relates to a coin slide construction of the type disclosed in my issued U.S. Patent No. 3,137,378, dated lune 16, 1964, and in my copending application Docket No. SK-10,526, led of even date herewith. The construction involves principally a means for latching the slide plate against full advancement whenever spurious coins, or no coins, are inserted in the coin apertures of the slide plate.

An object of the present invention is to provide irnproved means for latching the slide plate against full advancement whenever spurious coins, or no coins, are inserted in the coin aperture or apertures of the slide plate, said improved latching means being characterized by extraordinary coin-calipering accuracy, simplicity of construction and assembly, and freedom from servicing requirements.

Another object of the invention is to provide in a coin slide construction, means for latching the slide plate against full advancement, when spurious coins inserted into the coin aperture `of the slide plate are either undersized or oversized.

A further object of the invention is the elimination of small or delicate parts which are difficult to assemble or replace in servicing the coin slide, and which entail high labor costs in initial assembly at the factory.

Another object is to provide in a coin slide construction, improved coin-calipering and slide plate latching means which will effectively withstand the mistreatment and abuse to which coin-controlled equipment is often subjected when exposed to public use, and to adverse climatic conditions.

The foregoing and other objects are attained by the means described herein and illustrated upon the accompanying drawings, in which:

FIG. 1 is a bottom plan view of that portion of a coin slide which incorporates the improvements of the present invention.

FIG. 2 is an enlarged cross-sectional taken on line 2-2 of FIG. 1, showing the latches in full engagement with a slide plate keeper.

FIG. 3 is a cross-section taken on line 3-3 of FIG. 2.

"nited States Patet rice FIG. 4 is a view similar to FIG. 2, showing the latches partly though effectively engaging the slide plate keeper.

FIG. 5 is a cross-section taken on line 5-*5 of FIG. 4.

FIG. 6 is a view similar to FIG. 4, showing the latches held in a retracted or inoperative position by a solid portion of the slide plate.

FIG. 7 is a cross-section taken on line 7-7 of FIG. 6.

FIG. 8 is a view similar to FIG. 2, omitting the latches and the slide plate, and indicating bias of the caliper arms.

FIG. 9 is a cross-section similar to FIG. 4, showing the position of the caliper arms and the latches as an undersize coin undergoes calipering.

FIG. 10 is a view showing the elements of FIG. 9 displaced to a fully latched condition, as the result of an effort to forcibly advance the slide plate under conditions prevailing in FIG. 9.

FIG. 11 is a bottom plan view similar to FIG. 1, but embodying a modification of structure, and showing acceptable coins undergoing calipering.

FIG. 12 is an enlarged cross-section taken on line 12-12 of FIG. 11.

FIG. 13 is a cross-section similar to FIG. 12` but indicating a relationship of parts brought about by an undersized slug undergoing advancement lby the slide plate in FIG. 1l.

FIG. 14 is a view indicating the results of an effort to forcibly advance the slide plate under conditions prevailing in FIG. 13.

FIG. 15 is a cross-section similar to FIG. 12, but indicating a relationship of parts resulting from an attempt to operate the coin slide by means of an oversize coin or slug.

FIG. 16 is a bottom plan view of the coin slide structure embodying a second modification.

FIG. 17 is an enlarged cross-section taken on line 17-17 of FIG. 16, and showing the disposition of parts resulting from calipering of an acceptable coin.

FIG. 18 is a view similar to FIG. 17, showing the disposition of parts resulting from calipering of an oversize slug.

FIG. 19 is a view similar to FIG. 17, showing the disposition of parts resulting from calipering of an undersize slug.

FIG. 20 is a view similar to FIG. 19, showing disposition of the parts resulting from an attempt to advance the slide plate under the conditions prevailing in FIG. 19.

FIG. 21 is a fragmentary cross-section similar to that of FIG. 17, omitting certain parts and indicating bias of the caliper arms.

In all the drawing views, the reference numeral 24 indicates a coin slide plate or slider, which is longitudinally reciprocable relative to a stationary body member 26, between a fully retracted position and a position of full advancement. In the fully retracted position of the slide plate, one or more coins may be deposited in exposed coin-receptive apertures of the slide plate, for advancement with the slide plate toward the position of full advancement of the slide plate. The slide plate upon full advancement may initiate operation of a machine which vends an article or a service as is customary, and as eX- plained in my issued U.S. Patent 3,137,378 aforesaid.

Coins advanced by the slide plate may be subjected to a series of tests which determine acceptability of the coins, and should the coins prove unacceptable under test, they will be rejected and the slide plate will be latched in an intermediate position of advancement to preclude actuation of the vending machine associated therewith.

All of the foregoing is common practice in the art generally, and various forms of mechanisms have been employed more or less successfully to test coins or slugs and to prevent full advancement of the slide plate in the event that the coins or slugs prove unacceptable under test.

In accordance with the present invention, the slide plate 24 may be provided with an opening 28 similar to the opening 38 of my aforementioned patent disclosure, said opening 28 providing an abutment edge or keeper 30 adapted for engagement by a tooth 32 of one or more pivoted latches 34, 36, to stop the slide plate movement short of a full advancement. Either of the latches, or both, may so stop the slide plate 24; but if neither engages the keeper or abutment edge 30, as in FIG. 7 for example, the slide plate may be moved in the direction of the arrow (FIG. 7) to the position of full advancement. On the other hand, if either latch engages the keeper 30 either wholly or partly, as in FIGS. 3 and 5, respectively, the slide plate will be latched thereby in a position short of full advancement.

The latches 34 and 36 may be pivoted at 38 upon body member 26, or upon a stationary part thereof, the pivot 38 being offset from the plane of slide plate 24. In a preferred form of the latches, an elongate or oversize bearing 40 may be provided therein for reception of pivot 38, to

increase the sensitivity of latch movements toward slide plate opening 28.

With reference to FIG. 5, it is noted that latch tooth 32 may be undercut slightly, so that only the point of the tooth may engage keeper 30 of slide plate 24. Thus, if the tooth only partly enters keeper opening 28 as in FIG. 5, any force applied to slide plate 24 seeking to further advance it toward the right, will only displace the latch farther into opening 28, to the position of full engagement depicted by FIG. 3. Such displacement of the latch to full engagement is aided by the offsetting of pivot 38 from the plane of slide plate advancement, thereby preventing the tooth point from mutilating the keeper or shaving metal from the adjacent flat surface of the slide plate when the slide plate is forcibly advanced, with the latch only partially engaged.

As FIG. 7 plainly indicates, a latch such as 34, or 36, underlies the adjacent flat face 42 of slide plate 24 when the latch is out of register with opening 28.

Each latch 34 and 36 is provided with an actuator head 44, which may be in the form of a laterally extended at plate having a slot 46 formed therein. The at plate or head may be an integral part of the latch as shown, or if preferred, it may be a separate part rigidly fixed to the latch adjacent to tooth 32 and remote from pivot 38. The plane of the plate should be in substantial parallelism with the axis of pivot 38. Plate or head 44 extends laterally from the major axis of the latch, in a gizrection opposite to the direction of extension of tooth By means of forces applied to the slotted actuator heads 44, the latches may be moved to various positions between the extended or operative position of FIG. 3, and the retracted or inoperative position of FIG. 7, thereby to either lock or release the slide plate 24 in moving toward a fully advanced position, or toward the :right in FIGS. 3, and 7.

Referring now to FIGS. 1 and 2, the reference characters 48 and 50 indicate a pair of caliper arms, preferably crossed one over the other as shown, and each slidmgly projected through a slot 46 of the actuator heads of latches 34 and 36 (FIGS. 2 and 3). One of the caliper arms, such as S0, may be bowed or bent at 52, to ensure free lateral movement of the arms individually without contact one against the other.

The caliper arms have yanchor end portions 54, 54 secured as by means of rivets, screws, or other fasteners 56, 56 to the movable legs 58, 58 of a pair of pivoted coin-calipering rockers 60 and 62. The rockers may be supported upon a single pivot pin 64 having one of its ends xed relative to body member 26, so that the rockers may pivot about pin 64 to swing the free ends ot caliper arms 48 and 50 toward and from one another. A tension spring l66 having opposite ends thereof anchored to the rockers at projections 68, serves to constantaly bias the rocker legs 58, 58 outwardly from one another, which results in yieldingly biasing the free ends of the crossed caliper arms toward one another.

Coins or slugs C carried by slide plate 24 will be advanced by the slide plate from left to right in FIG. 1, with edges of the coins or slugs riding against stationary rails 70, 72 carried by body member 26. Such coins or slugs under advancement may strike and move the calipering lugs or shoes 74, 74 which extend rigidly fromI the legs 58 of the rockers into the path of advancement, thereby to swing outwardly the free ends of calipering arms 48, 50 by an amount dependent upon the diameter and/ or the thickness of coin or slug C. The rails and/or calipering shoes 74 may be equipped with shims, if desired, as taught by my aforesaid Patent No. 3,137,378; however, this feature may be considered irrelevant to the present invention.

From the disclosure of FIG. 1 herein, it will be understood that coins or inserts C which are genuine or acceptable, will swing the caliper arms 48, 50 further outwardly than will coins that are undersize; also, coins or inserts which are undersize may fail altogether to swing the caliper arms, or may swing them a lesser extent than will genuine or accetpable coins or inserts.

According to FIGS. 1 through 8, the slots 46 of the latch heads 44 are disposed obliquely to the plane of slide plate 24, thereby to provide inclined cam surfaces 76 against which may impinge the free end portions of caliper arms 48 and 50. FIGS. 2, 4 and 6 indicate, in progression, how outward movement of the caliper arms 48 and 50 may cam the latches 34 and 36 out of the opening 28 of slide plate 24, (see also FIGS. 3, 5 and 7). FIGS. 2 and 3 indicate an engaged condition of the latches with keepers 30, such as prevails when extremely undersized coins, or no coins at all, fail to spread apart the caliper arms 48 and 50 for samming the latches to a retracted position. The latches in this instance lock the slide plate against full advancement.

FIGS. 4 and 5 indicate a partial engagement of the latches with keeper 30, resutling from the advancment of undersize coins by the slide plate, and which spread the caliper arms insutliciently to cam the latches completely from slide plate opening 28. The latches here lock the slide plate against full advancement.

FIGS. 6 and 7 indicate a complete withdrawal of the latches from opening 28, resulting from an extreme outward movement of the caliper arms produced by advancement of acceptable coins through the calipering mechanism 70, 74 and 72, 74. The slide plate in this instance is unlatched, and may be projected to full advancement for actuating a vending machine.

As was previously pointed out herein, either of the latches 34, 36 act to curtail advancement of slide plate 24; that is, if one coin C of FIG. l is acceptable and the other is unacceptable, the unacceptable coin will fail to eiect a latch withdrawal and the latch so failing to withdraw will lock the slide plate against full advancement. Full advancement of the slide plate therefore is dependent upon the acceptability of both coins C, as determined by the calipering mechanism.

Of major importance to the present invention is the nature and the disposition of the caliper arms 48, 50, and of certain elements associated therewith. The reference character 78 denotes a transversely disposed rigid restraining bar located near the latch heads 44, and having an edge or track 80 upon which the caliper arms 48 and 50 normally may abut and slide as the caliper arms are moved toward and from one another incident to the passage of coins or slugs past the calipering shoes 74, 74. The track 80 is elongated in the direction of the width of slide plate 24, and is parallel to the plane of the slide plate. The restraining bar 78 carrying the track 80 is a stationary element, and may be tixedly mounted upon body member 26 in any suitable manner.

The track portion 80 of bar 78 is to be located at a distance from slide plate 24 substantially equal to the distance between the slide plate and that portion of cam slot 46 which is nearest the slide plate when a latch such as 34 or 36 is retracted or disengaged from the slide plate keeper (see FIG. 6). The cam slot 46 should be at least long enough to permit full engagement of the latch with keeper 30 (FIG. 2), while the caliper arm penetrating the slot remains in abutment upon track 80.

The caliper arms 48 and 50, unlike those of my aforesaid issued patent No. 3,137,378, are to tbe capable of exation in all lateral directions throughout their length, this being assured by forming them of a resilient wire or filament. A satisfactory material for the purpose may be tempered spring steel wire of about lf2-gauge size, having sufficient ductility to retain the bow or bend at 52, FIG. 1. A tempered stainless steel wire is preferred, due to its resiliency and resistance to corrosion. While a Wire circular in cross-section is preferred, wire of any other cross-sectional shape may perform the service required.

In assembling the coin-calipering unit comprising the arms 48, 50, the rockers 60, 62, and the anchorages 56, 56, it is imperative that the free ends of the arms 48, 50 be yieldingly :biased onto the restraining bar track 80, as in FIGS. 2, 4 and 6, so that the arms in moving toward and from one another, may normally slide along the track while shifting the latches toward and from slide plate opening 28. Under certain conditions, however, the caliper arms may flex away from track 80, as depicted by FIG. 10.

Flexing of the caliper arms away from track 80, as in FIG. 10, may occur when undersize coins or slugs are advanced iby the slide plate. Such coins or slugs may spread the free ends of the caliper arms only a limited distance, as in FIG. 9, Causing the latches to only partially engage the keeper 30 (see also FIG. 5). Then, if a patron attempts to use extraordinary force for further advancing the slide plate, the latch teeth 32 will `be cammed by the keeper into the fully engaged position of FIGS. 3 and 10, with the result that arms 48 and 50 will be lifted bodily from track 80 according to FIG. l0.

Displacement of the latches to the fully engaged position as above described is permitted by the resiliency of the caliper arms, without damage or permanent distortion of any operating parts. The caliper arms will return to their normal position upon track 80 as soon as the slide plate is retracted toward the normally inoperative position.

The resiliency of the caliper arms precludes also the possibility of permanent distortion or damage of parts that might result from the use of shims or other implements inserted into the coin slide for the purpose of manipulating the latches or the caliper arms to obtain free play without the use of proper coins. This is of utmost importance in avoiding frequent servicing of the coin slide mechanism.

FIG. 8 indicates by means of arrows, normal ybiasing of the caliper arms 48 and 50 resiliently against track 80 of the restraining bar 78, resulting from the use of resilient metal in forming the caliper arms. The track of the restraining bar will be seen to limit movement of the arms in only one direction, that is, away from the slide plate 24. In the direction of slide plate, 24, the caliper arm movement is unrestricted by the restraining bar.

FIGS. 1l through 15 illustrate a modification of the coin slide mechanism in which the caliper arms of resilient wire are employed. In the modified construction, coins or slugs C act to swing the caliper arms 82 and 84 apart -at the latches 34, 36, as previously recited in the description of FIGS. l through 10. A tension spring 86, as before, yieldingly urges the caliper arms in the opposite direction.

The heads or plates 44 of the latches, according to FIGS. 11-15, have formed therein cam slots 88 which are arcuate of configuration and sliding by receptive of the free ends of the caliper arms. By referreing to FIG. 12

it will be understood that outward shifting of the caliper arms 82 and 84 will cam the latches 34, 36 upwardly into slide plate opening 28; and inward shifting of the caliper arms will produce the same result. When the caliper arms are disposed at the high point of the cam slot, as in FIG. l2, the latches are withdrawn from opening 28, thereby permitting free reciprocation of slide plate 24.

The resilient caliper arms 82, 84 are yieldingly biased against the track of stationary restraining bar 78, as in FIGS. 1 and 2 previously described, and under normal operating conditions the arms will remain in contact with the track while sliding thereon between positions at opposite ends of cam slots 88.

The caliper arms 82, 84 may leave the track 80 (FIG. 14), under certain conditions, as when a coin or slug C is slightly oversize or slightly undersize, resulting in a partial engagement of a latch with keeper 30 (FIG. 15). If the latch or latches be only partially engaged, and an attempt is made to further advance the slide plate by force, the latch or latches will be driven to the position of full engagement with the keeper according to FIG. 14, by camming action of the latch tooth against the keeper as was explained previously in describing FIGS. 2 through 5. Failure to advance the slide plate because of the full latch engagement, followed by retraction of the slide plate, will permit the return of the caliper arms to the normal position of fbias against track 30.

The track portion 80 of restraining bar 78 is to be located at a distance from slide plate 24 substantially equal to the distance between the Slide plate and that portion of cam slot 88 which is nearest the slide plate when a latch such as 34 or 36 is retracted or disengaged `from keeper 30. Cam slot 88 should be at least long enough between its central high point and the slot ends, to permit full engagement of the latch with keeper 30 while the caliper arm associated therewith remains in abutment upon track 80. Opposite ends of slit 88 should tbe equidistant from slide plate 24.

The structure of FIGS. 11 through 15 is designed to caliper coins or slugs which are oversize, undersize, or acceptable in size, and to latch the slide plateagainst full advancement upon any attempt to operate the coin slide with the use of either undersize or oversize coins or slugs.

With further reference to FIG. 11, it is noted that the anchored end portions of the caliper arms may be secured to the Dockers 9G and 92 by twisting them about the projections 68, 68 which support the tension spring 86. Spring 86 yieldingly biases the rockers about stationary pivot pin '94. The rocker legs 96, 96 which carry the calipering lugs 74, 74, may be provided with adjusting screws 98, 98 for adjustably positioning the free ends of caliper arms 82, 84 between opposite ends of cam slots 88. The adjusting screws 98 may be formed with screwthreaded Shanks 10G, 100 eccentric to the screw heads, so that upon slight rotation of the adjusting screws relative to the rocker legs, the caliper arms resting yieldingly against the eccentric shanks may be moved toward and from one another for adjustment purposes. The screw Shanks 108 may threadedly engage'suitable tapped holes formed in rocker legs 96, 96, as will be understood.

The caliper arms 82, 84 may be mounted upon the rockers 96 as above described, or in any other suitable manner, of which FIG. 1 may be an example. In fact, any conventional mechanical connection might be employed for mounting the caliper arms upon the rockers for movement therewith, so long as it permits biasing of the free ends of the caliper arms against the restraining bar track 80.

FIGS. 16 through 21 illustrate a modification of structure, wherein the sl-ots 102 of the latch heads are straight, and parallel to the plane of slide plate 24. Since the slots 102 are not inclined as are those of FIGS. 2 and 12 for example, they may not perform as cams to project and withdraw the latches 34, 36 relative to slide plate opening 28. It is therefore necessary to provide stationary cam members such as 104, 106, 108, to effect movement of the latches toward and from keeper 30 as the free ends of caliper arms 110 and 112 shift toward or from each other.

Each cam member has a pair of inclined cam surfaces or edges 1'14 and 116 ('FIG. 2l), convergent to an apex or high point 118 spaced from the track 80 of restraining bar 78. The low points of each cam member may be located at or near track 80, where the resilient caliper arms 110 and 112 normally rest according to FIG. 2l, the arms being biased yieldingly toward track 80.

The cam members 104, 106, 108, may be formed of thin sheet metal plates which in vertical cross-section are U-shaped, so that the cam members may be clipped onto restraining bar 78 and held thereon by frictional gripping, (see FIG. 16). AS indicated by broken lines on FIG. 2l, the cam members may be slid lengthwise along bar 78 to desired positions of adjustment in spacing one from another.

When the caliper arms are moved toward one another, according to the broken lines 110 and 112 in FIG. 21, the arms climb the cam faces of cam member 106, thereby to yieldingly urge the latches 34, 36 toward the slide plate 24, for engagement with keeping 30 of FIG. 19. FIG. 19 shows the latches only partially engaged with keeper 30, as the result of calipering a slightly undersize coin or slug. The calipering of coins or slugs which are more extremely undersize, will of course effect a more extensive movement of the caliper arms toward the apex of cam member 106, thereby to move the latches into full engagement with keeper 30.

If the coins or slugs undergoing calipering are oversize rather than undersize, the caliper arms will be moved outwardly, as in FIG. 18, causing them to climb the adjacent cam surfaces of members 104 and 108, for urging the latches toward the slide plate or into keeper opening 28, to engage the keeper and thereby limit advancement of slide plate 24. Quite obviously, the extent to which a coin or slug is oversize will determine the extent to which a latch will engage keeper 30.

Should latch engagement be only partial, as in FIGS. 18 and 19, any attempt to fully advance the slide plate by force will displace the latches to full engagement with keeper 30 (see FIG. 20), due to the camming action of the keeper against the latch teeth as was explained in the description of FIGS. 5 and 3. Such displacement of the latches requires that the caliper arms 110, 112 be resilient and shiftable in the direction of the slide plate in accordance with FIG. 20, so that the caliper arms may break contact with the triangular cam members as there indicated. The caliper arms are normally yieldingly biased onto the cam members, and may be anchored to the rockers of the calipering mechanism in accordance with FIGS. l or 11, or otherwise.

The structure illustrated by FIGS. 16 through 2l will caliper coins or slugs which are oversize, undersize, or acceptable in size, and will effect latching of the slide plate against full advancement upon any attempt to operate the coin slide mechanism with the Iuse of either oversize or undersize coins or slugs. The resiliency of the caliper arms ensures against damage or permanent distortion of operating parts in the event of any attempt made to obtain free play by the insertion and manipulation of shims or other implements into the coin slide mechanism. The need for frequent servicing or repairs is thereby eliminated.

The latch in all forms of the invention may be constructed in accordance with FIGS 1, 2 and 3, except for the nature and disposition of the cam slot thereof; and as previously suggested herein, the cam head of the latch may desirably be a separate part rigidly fixed to the body of the latch, with possible fabrication advantage.

What is claimed is:

1. A coin controlled device comprising in combination: a slide plate including means to advance a coinlike insert, said slide plate being shiftable between an initial position of retraction and a position of full advancement; a body member reciprocably supporting the slide plate in a plane of advancement; a coin caliper member pivoted relative to the body member and including a calipering shoe disposed along the path of advancement of the coin-like insert; means for directing the coin-like insert against the shoe for moving said shoe and the pivoted caliper member incident to advancement of the slide plate; a keeper on the slide plate; a latch supported by the body member for movement to engaged and disengaged positions with respect to said keeper, said keeper being so located upon the slide plate that engagement thereof with the latch stops advancement of the slide plate prior to a full advancement of the slide plate; and means for imparting to the latch the movements of the coin caliper member, said means including an elongate arm of resilient spring wire flexible in all directions laterally of its length, said wire having one end anchored to the caliper member, and an opposite end portion connected to said latch for movement therewith.

2. The device as specified by claim 1, wherein the combination includes restraining means for limiting exation of the resilient arm in the direction of latch disengagement.

3. The device as specified by claim 1, wherein said resilient spring wire is of stainless steel of approximately l2gauge thickness.

4. The device as specified by claim 2, wherein said restraining means includes a fixed elongate track in spaced substantial parallelism with the plane of the slide plate, said track extending transversely of the path of slide plate advancement in position to support said opposite end portion of the resilient arm.

5. The device as specified by claim 2, wherein said restraining means includes an undulatory track for guiding the resilient arm toward and from the plane of the slide plate as said arm moves with the calipering shoe, said arm being constantly yieldingly biased onto said track by the inherent resiliency of said arm.

6. The device as specified by claim 4, wherein said opposite end portion of the resilient arm is constantly yieldingly biased against said track; and the combination includes means for lifting the arm from contact with said track incident to movement of the latch to a position of engagement with the keeper aforesaid.

7. The device as specified by claim 6, wherein the means last mentioned comprises a cam carried by the latch and operative upon said opposite end portion of the resilient arm for lifting said arm from the track.

8. The device as specified by claim 6, wherein the combination includes: means responsive to force applied to the slide plate, for displacing the latch from a position of partial engagement with the keeper, to a position of full engagement therewith.

9. The device as specified by claim 7, wherein the combination includes: means responsive to force applied to the slide plate, for displacing the latch from a position of partial engagement with the keeper, to a position of full engagement therewith.

10. The device as specified by claim 8, wherein said means for lifting the arm includes a cam carried by the latch and operative upon said opposite end portion of the arm for lifting said arm from the track.

11. The device as specified by claim 8, wherein said means for lifting the arm includes cam means modifying the contour of the track, said cam means being operative upon said opposite end portion of the resilient arm, for lifting said arm away from said track.

12. The device as specified by claim 11, wherein said cam means is adjustable to assume selected positions along the length of the track.

13. The device as specified by claim 10, wherein said cam is defined by an elongate slot disposed obliquely to the plane of movement of the slide plate.

14. The device as specified by claim 10, wherein said cam is defined by an elongate arcuate slot having opposite ends and a middle portion, said middle portion being closer to the plane of the slide plate than are said opposite ends, and said opposite ends being Substantially equidistant from the plane of the slide plate.

15. The device as specified by claim 10, wherein said cam is dened by an elongate arcuate slot having opposite ends and an intermediate portion, said intermediate portion being disposed at a different distance from the plane of the slide plate than are the opposite ends of the slot. 10

References Cited UNITED STATES PATENTS 3,106,278 10/1963 Hall 194-92 3,137,378 16/1964 Hall 194-92 3,231,059 1/1966 Hall 194-92 3,354,998 11/1967 Hall 194-57 WALTER SOBIN, Primary Examiner.

U.S. C1. X.R. 194--102 

